Features

• Complete High Power PD Interface Controller
• IEEE 802.3af® Compliant
• Onboard 750mA Power MOSFET
• Complementary Power Good Outputs
• Flexible Auxiliary Power Options
• Precision Dual Current Limit with Disable
• Programmable Classification Current to 75mA
• Onboard 25k Signature Resistor with Disable
• Undervoltage Lockout
• Complete Thermal Overload Protection
• Available in Low Profile (4mm × 3mm) DFN Package

Typical Application

Description

The LTC4264 is an integrated Powered Device (PD) interface controller intended for IEEE 802.3af Power over Ethernet (PoE) and high power PoE applications up to 35W. By including a precision dual current limit, the LTC4264 keeps inrush below the IEEE802.3af current limit levels to ensure interoperability success while allowing for high power PD operation. The LTC4264 includes a field-proven power MOSFET delivering up to 750mA to the PD load while maintaining compliance with the IEEE802.3af standard. Complementary power good outputs allow the LTC4264 to interface directly with a host of DC/DC converter products. The LTC4264 provides a complete signature and power interface solution for PD designs by incorporating the 25k signature resistor, classification circuitry, input current limit, undervoltage lockout, thermal overload protection, signature disable and power good signaling.

The LTC4264 PD interface controller can be used along with a variety of Linear Technology DC/DC converter products to provide a complete, cost effective power solution for high power PD applications.

The LTC4264 is available in the space-saving low profile (4mm × 3mm) DFN package.